Sound reproducing mechanism



July 19, 1932. T. H. PARKER 1,868,396

I SOUND REPRODUCING MECHANISM Filed Jan. 20, 1930 Patented July 19, 1932UNITED STATES THOMAS HUGH PARKER, 0F BOSHAM, ENGLAND SOUND REPRODUCIN GMECHANISM Application filed January 20, 1930, Serial No. 422,198, and inGreat Britain January 21, 1929.

This invention relates to Vibration transmitting arms for use in soundreproducing mechanism.

The object of the present invention is to produce a vibrationtransmitting arm which while having the necessary rigidity is veryflexible and permits of a large magnification of the vibrationstransmitted.

According to this invention the vibration transmitting arm consists of acircular ring of thin flexible metal having an arm extending bothinwardly to the centre of the ring and outwardly tor a short distancebeyond the periphery of the ring.

The ring is of approximately the same diameter as the sound box,pick-up, loud speaker or ear phone to which it is to be applied and issecured thereto. The inner end of the arm is secured to the diaphragm ofthe sound reproducer, and the outer end is secured to the part whichsets up the vibrations to be transmitted.

The ring of metal is insulated from the casing of the sound box,pick-up, loud speaker or ear phone, to which it is secured, by means ofrubber or other resilient packing.

The device can be used as the stylus arm of a gramophone sound box, thestylus being secured to the outer end of the arm and the inner end ofthe arm being secured to the centre of the diaphragm, the ring partbeing secured to the sound box casing. Or, if it is to be used with aloud speaker, the outer end of the arm would be secured to the armatureof an electric-magnet, the inner end of the arm being secured, asbefore, to the diaphragm of the loud speaker, the ring part beingsecured to the loud speaker unit.

My invention is illustrated in the accompanying drawing in which Fig. 1shows the vibration transmitting arm in plan view adapted for use as thestylus arms of a gramophone. Fig. 2 is a detail transverse section of asound box provided with my improved vibration transmitting arm.

As shown the armconsists of a circular ring 1 of thin flexible metalhavin an arm extending inwardly to the centre 0 the ring as at 2 andoutwardly for a short distance beyond the periphery of the ring as at 3.

The inner end 2 of the arm is provided with means (not shown) forsecuring it to the centre of a diaphragm, and the outer end 3 of the armis provided with a hole for the insertion of the stylus 4, and a screw 5for holding same in position.

The ring 1 is secured, between rubber or other insulating resilientpacking, to the sound box casing indicated at 6 by screws or othersuitable means.

I claim A vibration transmitting device, for use in sound reproducingmechanism, consisting in combination with a sound box of a ring of thinflexible metal arranged in the sound box and having an arm extendingboth inwardly to the centre of the ring and outwardly for a shortdistance beyond the periphery of the ring and made in one piece with thering, said ring being secured to the sound reproducing mechanism.

In testimony whereof I have hereunto set my hand this 8th day ofJanuary, 1930.

THOMAS HUGH PARKER.

